fix: sort terraform autodiscovery manifest during test

[olblak]

fix: https://github.com/updatecli/updatecli/actions/runs/6335541299/job/17208054420

When the tests for the Terraform autodiscovery plugins are executed, they don't necessarily generate manifests in the same order which leads to failing tests when we compare the result with expected results.

So this PR introduce a sort function that can be used during the test to ensure the expected manifest and generate manifests are sorted the same way.

Test

To test this pull request, you can run the following commands:

pkg/plugins/autodiscovery/terraform/test/
while true; do GOFLAGS="-count=1" go test ./... && sleep 1; done;

Additional Information

Tradeoff

Potential improvement

This problem can also affects the other autodiscovery plugins so we may decided to update the expected result over there as well.